Deleted all files from 'My Files' now lost most of factory default tones...Help!

HELP.. I have a Samsung Galaxy s4 Mini.I was advised to go into my files and move pics, videos and music to SD card so I did but then I noticed that majority of the random files that kept popping up and creating their own folders were empty files. I stupidly deleted them but also the files that I tought were irrelevant!
My phone now has changed my ringtone (which I found and restored, custom that was on SD card) and notification tones.
However, my problem is the message tone that I had had since getting the phone has disappeared along with other factory default tones and now I am left with only about 7 default tones and my message notification says 'unrecognised tone'
HOW DO I RESTORE MY MISTAKE OR GET MY MUCH LOVED NOTIFICATION TONE BACK?
All help is appreciated!